EP0476026B1 - Process and device for registering and checking items - Google Patents

Abstract

PCT No. PCT/FR90/00423 Sec. 371 Date Feb. 7, 1992 Sec. 102(e) Date Feb. 7, 1992 PCT Filed Jun. 14, 1990 PCT Pub. No. WO90/16051 PCT Pub. Date Dec. 27, 1990.In particular for reducing the waiting time at the checkouts of self-service supermarkets, articles are registered by providing each article with a microcircuit (24) having a loop for picking up high frequency energy and for responding to an interrogation by transmitting a modulated message at high frequency representing an article-identifying signature. An article (20) is taken into account by exciting its microcircuit by applying an energy-supplying and interrogation high frequency signal thereto to cause it to transmit the modulated signal of the signature, the modulated signal is picked up by memory means causing the signatures to correspond to the prices of articles, the price of the interrogated article is stored in a memory, and it is displayed, and the price of the article is added to that of any articles that may previously have been taken into account.

Description

The invention relates to accounting methods and devices (this term being to be interpreted as designating the taking into account and the totalization of the price of items purchased) and to item monitoring and it finds a particularly important, although not exclusive, application. , in self-service large-scale stores.

At present, a major criticism made by barges at department stores of this type is the waiting time at checkouts, necessitated by the one-by-one control of the items purchased, registration and payment. The use of scanning devices for optical reading of bar codes carried by each item saves time by avoiding the cashier to enter the code or the price of each item individually on an accounting machine. This solution is however only a palliative because, due to the individual verification of each item by an employee, the time spent by each customer at a checkout is practically proportional to the number of items purchased, the collection time generally representing a small fraction of the length of stay at a cash register. The taking into account indeed requires the deposit on a carpet of all the articles, their individual verification, then their reloading.

Another source of dissatisfaction is the near impossibility for the barge to check that the price actually recorded is indeed the one he noted on the shelf. Finally, a reluctance of the customer is the fact that he can only estimate very roughly the amount he will have to pay until the total is displayed at the checkout.

A method and a device are already known in accordance with the preamble of claims 1 and 3, respectively (FR-A-2 555 339).

There has been proposed (US-A-4,373,133) a method of providing each customer receptacle with a barcode reader and a totalizer. The check carried out at the checkouts is very summary and facilitates fraud, since it consists in checking that the total weight of the items purchased corresponds to what it should be according to the bar codes read.

We also know (FR-A-1,598,252) a label intended for automatic sorting of objects, capable of providing a high frequency signal in response to a high frequency interrogation signal. There is also known (WO-A-86/04171) a portable label identification system providing a coded electric field when it receives energy by magnetic means.

The invention aims to provide a method and a device which meet the requirements of the practice better than those previously known, in particular in that they eliminate the above defects or at least reduce them.

To this end, the invention proposes in particular a method according to claim 1 and a device according to claim 5.

The time required to interrogate all the articles can be very reduced by implementing a sequence of interrogations comprising tests allowing each one to determine if there exists at least one article in a given group (corresponding for example to the same value of the most significant bits of the signature), omitting the query relating to all the articles in the group if the test reveals that there are none.

• la Figure 1 est un schéma de principe d'un dispositif dans lequel la prise en compte d'un article exige du chaland qu'il effectue une opération de lecture distincte du transfert de l'article d'un rayon à un réceptacle ;
• la Figure 2 est un synoptique de principe de l'électronique incluse dans le dispositif selon la Figure 1 ;
• la Figure 3 est un schéma de principe d'un dispositif selon un mode de réalisation de l'invention ;
• la Figure 4 est un logigramme montrant un exemple de séquence lors des opérations de comptabilisation qui interviennent lors du passage sous un portique dans le mode de réalisation de la Figure 3.

The invention will be better understood on reading the following description of a particular embodiment, given by way of example. The description refers to the accompanying drawings, in which:

• Figure 1 is a block diagram of a device in which taking an article into account requires the barge to perform a reading operation separate from the transfer of the article from a department to a receptacle;
• Figure 2 is a block diagram of the electronics included in the device according to Figure 1;
• Figure 3 is a block diagram of a device according to an embodiment of the invention;
• FIG. 4 is a flow diagram showing an example of a sequence during the accounting operations which take place during the passage under a gantry in the embodiment of FIG. 3.

A device can have the basic material constitution shown in FIG. 1. This device is carried by a lockable frame 10 on the top of a carriage 12, for example using a lock making it possible to remove the frame 10 from the checkout when the barge wants to push the cart to a parked vehicle. The frame 10 carries an electronic unit 14 provided with a display 16 and a reader 18.

Each of the items made available to the barge contains an identification label 24 inaccessible to the barge as long as the packaging is intact. Each of the labels 24 contains a microcircuit and is deprived of an active autonomous source of energy. However, this microcircuit comprises means for collecting high frequency energy, means for transmitting an identification signature of the article in response to the reception of an interrogation code constituted by a modulation of a carrier. at high frequency F1, and means for storing sufficient energy to allow the microcircuit to operate.

In the embodiment shown in Figure 2, the microcircuit incorporated into each label includes a supply loop 26 intended to be placed in a high frequency field F1. This loop is generally formed by a spiral track. It is connected to a rectifier circuit 28 for storing energy on a capacitor 30. The loop 26 also serves as a sensor for the interrogation code which is the same for all the articles in the embodiment of FIG. 2.

An interrogation code detection branch comprises a bandpass filter 32 intended to isolate the interrogation frequency F1, a clock recovery circuit 34 and a decoding circuit 36. When this circuit identifies the interrogation code , it excites a circuit 38 for transmitting the signature of the article, in the form of a signal at a high frequency F2, modulated in amplitude or in frequency. The signature is for example constituted by a word of several bits. The signal frequency modulated F2 is applied to the loop which then serves as the transmitting antenna.

The microcircuit also comprises a deactivation member 42, capable of inhibiting the code transmission circuit 38 when the article which contains the microcircuit has been taken into account, as will be seen below.

• de provoquer la transmission, vers le microcircuit de l'article, d'un ordre d'inhibition excitant le circuit 42,
• d'émettre, vers les moyens de comptage de l'afficheur 16, un top de confirmation 56 lorsque le circuit d'émission 38 du microcircuit cesse d'émettre la signature, par suite de son inhibition.

The electronics 14 comprises for its part a transducer 44 provided with an antenna (not shown) making it possible to radiate a high frequency field F1 and to supply a signal when it is placed in a high frequency field F2. The electronics comprise an interrogation branch, constituted by a memory 46 for storing the interrogation code and a generator 48 of a signal constituted by a carrier at frequency F1, pure or modulated by the interrogation code 46. A receiving branch comprises a decoding circuit 50, generally provided with an input bandpass filter centered on the frequency F2 and a programmable transcoding read-only memory 52 corresponding, with each signature of an article, to a price and possibly an indication identification. The output of the read only memory is applied to the drive circuit of the display 16, provided with totalization means. In the embodiment shown, this drive circuit of the display is connected to a validation and inhibition circuit 54 whose role is:

• to cause the transmission, to the microcircuit of the article, of an inhibition order exciting the circuit 42,
• to send, to the counting means of the display 16, a confirmation top 56 when the transmission circuit 38 of the microcircuit stops transmitting the signature, as a result of its inhibition.

The emission of this confirmation top can be indicated to the barge by an audible and / or visual signal.

For simplicity, FIG. 2 does not show the power supply of the various circuits any more than the conventional clock and synchronization circuits of the electronic unit 14.

The operation of the device which has just been described is as follows.

The barge who wants to buy an item must, before placing it in the cart 12, take it into account. For this, it scans either a determined area of the article (in the case where the location of the label is visible from the outside), or the entire article using the reader 18, which contains the transducer 44. A drive switch with excitation push button 18 can be provided in order to avoid making it operate continuously. The reader then transmits successive and separate sequences each consisting of an initial continuous train intended to supply the energy required to charge the capacitor 30 of the microcircuit, then a train modulated according to an interrogation code.

When the microcircuit is in the transmission field and identifies the interrogation, it responds by transmitting, on its loop 26 and during the silences separating the sequences transmitted by the electronic unit 14, a signal constituted by a high frequency carrier F2 , different from F1, modulated according to a signature characteristic of the article. The decoded signature is transmitted to the programmable transcoding read-only memory 52, which can be updated periodically. The output of the memory shows, on the display 16, the price of the item and possibly the indication of its nature.

As soon as the taking into account is effective, the drive circuit of the display excites the inhibition circuit 54 which applies to the transducer 44 a signal intended to inhibit the emission circuit 38 of the microcircuit. The inhibition order can be transmitted at the frequency F1, in particular if the interrogation has stopped. Upon receipt of the inhibition order, there is no longer a signature sent by the microcircuit. This cessation is detected by the decoding circuit 50 (the transmission stop can be replaced by the sending of a final inhibition indication word). The finding of the inhibition causes the issuance of a confirmation order to take the article into account by the circuit 54 and to add the price of the article to the total amount already taken into account.

The device is supplemented by control means, located at a location where all the items purchased pass. One solution is to provide a location upstream of each of the payment boxes. This location can be materialized by a gantry under which the receptacle passes. The gantry (not shown) contains electronic transmission of sequences identical to those provided by the generator 48 of each electronic block 14, but provides an electromagnetic field much more intense than the readers, so as to be able to excite the microcircuits of all items passing through the inspection location.

If one or more of the microcircuits have not been inhibited, the corresponding signature is issued. The detection means at the location delimited by the gantry must be more sensitive than those of each electronic unit 14, since the transducers can be moved away from the microcircuits.

To avoid damaging the uninhibited microcircuits during their passage to the control location, where the energy received by the loop 26 is in some cases much higher than during normal reading, the energy storage means 28 can be provided with load limiting means (not shown). In practice, it is sufficient to have a capacity supplying the energy necessary for the emission of a signal of a few milliseconds.

In the embodiment of the invention shown schematically in Figure 3, the microcircuit contained in each article has elements similar to those shown in Figure 2 and which, for this reason, are designated by the same reference number. There is, in the microcircuit of Figure 3, a power supply loop 26 connected to a rectifier 28 provided with an energy storage capacitor 30. An interrogation code detection branch comprises a bandpass filter 32 , a clock recovery circuit 34 and a decoding circuit 36. This circuit is for example provided for supplying in series, on its output 38, the V bits of a word representing the signature of an article which one seeks to determine presence. The successive bits are loaded into a shift register 40 connected to a V-bit comparator 42 which also receives the identification signature of the article in question, stored during manufacture in a read-only memory 44. In order to make the search for items brought to the reading location, the comparator 42 is advantageously provided to supply a first signal, on an output 46, when there is coincidence between a determined fraction of the signature stored in 44 and the corresponding fraction provided by the decoder 36 and a second signal, on an output 48, in the event of complete coincidence. These signals are applied to a frequency generator F2 modular to apply, to loop 26, a different signal depending on whether there is simply observation of the identity of certain bits (V _{m most significant} bits for example) and a second signal in the event of complete coincidence.

If we now assume that the detection location is materialized by a gantry 51 placed immediately upstream of the boxes, this gantry is associated with means making it possible to identify and take into account sequentially the different items placed, for example in a cart brought under the gantry.

The gantry comprises a signal generator at frequency F1 associated with a modulator 53 making it possible to code short pulses at frequency F1 by interrogation codes corresponding to the signatures of the articles likely to be under the gantry. The generator 52 is connected to an antenna contained in the gantry. This antenna is also connected to a reception channel comprising a set of frequency filtering F2, of decoding and identification of presence messages supplied by 50. This set, designated by 56 in FIG. 3, controls, in the event of recognition , taking into account the item identified by means comprising a transcoding table (programmable read-only memory 58 which causes the price of the product to be taken into account and the corresponding data to be displayed, by a display 60). The signature identifying the product is applied to the transcoding table 58 by 53.

The device is completed by confirmation means which can be of the same kind as those shown in Figure 2.

• dans une première étape, on détermine s'il existe des articles dont la signature appartient au sous-groupe dont les bits de poids fort représentent un nombre déterminé, tous les nombres possibles N étant testés en succession,
• uniquement dans le cas où le test a révélé la présence d'un article au moins, tous les nombres représentables par les bits de poids faible sont interrogés à leur tour.

The interrogation and taking into account flow diagram can be that shown in FIG. 4, in a relatively rudimentary embodiment according to which, each item being designated by a signature of V bits, of which V _{m most significant} bits representing a number between a determined value N₀ and a maximum value N _m and least significant bits defining a number between n₀ and a maximum value n _m :

• in a first step, it is determined whether there are articles whose signature belongs to the subgroup whose most significant bits represent a determined number, all the possible numbers N being tested in succession,
• only if the test has revealed the presence of at least one article, all the numbers represented by the least significant bits are queried in turn.

At the start of the operation (FIG. 4), a test 62 is carried out to determine the presence of articles whose most significant bits represent a predetermined initial number N₀ (which may be zero). If the test gives a negative result, N₀ is incremented by one. Before carrying out the test 62 again, a check 64 that the new value N₀ does not exceed the maximum N _m is carried out: in the latter case, the process is terminated.

If the test indicates that there is at least one article, an interrogation is made for each of the numbers represented by the least significant bits, by comparison between n and n₀ (first an initial value which can be zero, then values to be incremented each time by one).

In the event of complete coincidence, there is display and recognition, then return to the start of the loop.

In a more elaborate embodiment, making it possible to reduce the number of unsuccessful attempts, the flow chart comprises a greater number of loops. The first test is performed only on the most significant bit. Then the successive tests are performed on two bits, three bits, etc.

The duration of an article identification sequence can be reduced to around 10 ms, which, even for a very large number of articles, makes it possible to reduce the duration of parking at the reading location to one second about.

The interrogation mode which has just been described, using an identification by binary modulation in baseband, is in default when several identical articles are contained in the cart. This drawback can be eliminated by extending the article code by 3 or 4 digits. When manufacturing a batch (carried by a pallet) all the articles in this batch are given the same article code, but a different extension number (from 000 to 999 or from 0000 to 9999) is added to it.

It is therefore unlikely that the customer will take two identical items on the shelf with the same extension code. Then simply continue in depth with the "questionnaire" to be able to count all of the items for sure.

To allow the customer to know the total amount of his purchases before he goes to the cash desks, tunnels each provided with a gantry similar to that of the cash desks and a display, or even a printer, can be distributed in various locations of the store.

The customer just has to go with his cart through one of these tunnels to find out the total amount of his purchases.

Claims (8)

1. Method for entering into account and checking out articles, comprising the steps of circulating each article (20), which carries a microcircuit (24), through a read-out and counter device (52) which determines the price of each article (20); electronically storing the price of the article (20); automatically adding the price of the article to the price of articles possibly entered into account earlier; providing each microcircuit (24) with means for collecting high frequency energy (26,28,30); and circulating all purchased articles (20) through a location (51) where high frequency energization and interrogation field (F1) prevails,
      characterized in that the microcircuit is provided with transmitting means (26,50) which, in response, transmits a modulated high frequency message (F2) which represents a signature which identifies the article; the microcircuit (24) is energized at a path location where the high frequency energization and interrogation field (F1), with which successive interrogation calls assigned to all possible articles are generated; the modulated message (F2) is collected with memory means; and the price of each article is derived from the signature thereof (56,58).
2. Method according to claim 1, characterized by carrying out a sequence of interrogations comprising tests each for determining whether there exists at least one article in a given group, omitting an interrogation relating to all articles of the group, if the test indicates there is none.
3. Method according to claim 2, characterized in that each test consists in determining whether there are articles whose signature comprises MSBs of predetermined value.
4. Method according to claim 3, characterized in that the first test is only carried out on the most significant bit and the successive test on two bits, three bits, etc.
5. A device for entering into account and checking out articles each containing a microcircuit which has means for collecting high frequency energy (26,28,30), the device comprising a read-out and counter unit (52) which identifies the price of each article (20), stores it and adds the price of the article to the price of the articles possibly taken into account earlier; and which further comprises means for transmitting high frequency interrogation energy (52),
      characterized in that the microcircuit is provided with means (50) which transmit, responsive to the high frequency interrogation code (F1), a modulated message which represents a signature identifying the article (20) and in that the read-out unit comprises a gateway (51) which defines a location where each article is detected and all articles are taken into account, which comprises a generator (52, 53) of successive interrogation codes (F1) corresponding to the signatures of the articles possibly located under the gateway (51) and which comprises memory means (56) for picking up the modulated signature signal transmitted in response by the microciruit (24) and gives the corresponding article price (56,58).
6. Device according to claim 5, characterized in that it comprises distributed read-out units, each comprising an additional gateway provided with a display indicating the total purchased amount.
7. Device according claims 5 or 6, characterized in that, the signature of each article consisting of MSBs and LSBs, said generator (52,53) and the memory means are provided for determining, during a first step, whether there are articles whose signature belongs to the group whose MSBs represent a predetermined number and for trying the numbers represented by the LSBs only if there exist articles belonging to the group.
8. Device according claims 5, 6 or 7 characterized in that the signature comprises, in addition to an article code which is common to all articles which are identical, a variable extension number.

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